Charles batchbloe



(No Model.) I

C. BATCHELOR.

DYNAMC ELECTRIC MACHINE.

\ 170.372,447. Patented Nov. 1, 1887.

m'lmlilll'lMMMIUIHHWWNNMHMHIIHUH lllilllllll IIIIIIIIIIIIIIIH@ UNITED STATES PATENT OFFICE.

CHARLES EA'TcHELoR, 'on NEW Youn, n. Y.

DYNAlVlO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent. No. 372,447, dated November 1, 1887.

Application tiled February 23, 1887. Serial No. 223,480. (No model.)

To aZZ whom it may concern.-

Be it known that I, GHAnLEsBaTei-TELOR, of the city of New York, in the county and State ofNew York,have invented a certain new and useful Improvement in Dynamo-Electric Machines, of which the following is a specification.

My invention relates to armatures for dynamo-electric machines of that class in which the armature-core is composed ofa number of thin plates placed upon thc shaft and massed closely together, with thin insulation interposed between them. In such armatures two Ways of holding the core-plates together upon the shafthavc heretoforebeen employed. In one construction the-plates at the 'ends of the core are made thicker than the rest of the plates, which are of thin sheet-iron, and these end plates are keyed on the shaft, while the thin plates are placed loose thereon and secured by several bolts passing through the whole length of' the core, by means of which the plates and insulation are drawn and held close together. In this construction it is found when the machine is in operation that the bolts after a time become loose, because when the machine is started, while the heavy plates keyed to the shaft receive the motion at once, such motion is transmitted to the plates which form the mass of the core through the bolts, and the inertia ofthe heavy mass tends to delay lits starting, so that a considerablestrain is brought on the bolts. The same occurs in stopping the machine, and the bolts and boltholes are thus gradually worn away, so that the plates become in time loose thereon and may move independently of one another, whereby, as will be readily seen, the usefulness of the machine is impaired. Another construction is to have, as before, the thicker end plates keyed to the shaft and the thin plates loose on the shaft between them, and to bring the plates close together by heavy nuts placed on screw-threaded portions ofthe shaft at the ends of the core and screwed up tightly against the end plates. In this construction, also, the plates work loose in time,though not to as great an extent as in the form first described. Such first-described Vform is, however, a better one forlargc machines than the other.

The object of my invention is mainly to so construct an armature o f the character described as to avoid the defect referred to, and also to improve the insulation of such armatures; and my invention consists in the novel devices and combinations ot' devices employed by me in accomplishing these objects, as hereinafter set forth and claimed.

My invention is illustrated in the accompanying drawings, in which- Figure l isalongitudinalsection of an armature-core and its shaft embodying my invention, the core being of that class in which the plates are held together by bolts; Fig. 2, a transverse section of the same, and Fig. 3, a longitudinal section of a core in which the qplates are held together by nuts on the shaft,

the shaft being shown in elevation.

A is the shaft,and B the armature-core. Such core is made up of a large number of thin sheet-iron plates a, with thicker end plates, b, and, preferably, also a thicker middle plate, c. These plates are all insulated from each other, either by thin sheets of paper or similar material between them or by an insulating varnish placed upon the plates.

In Figs. I and 2, bolts d extend through all the plates of the core, having nuts upon their ends, by means of which the plates aredrawn as close together as possible. The bolts are surrounded by insulating material, e, preferably a Wrapping of mica.

Upon that portion of the shaft on which the core is placed is formed a continuous keyway,

f, and in the same is iuserteda key, g, extending continuously the whole length ofthe core. All the plates, both the thick end and middle plates and the thin plates which make up the body of the core, are provided with slots h, 9o

which fit the key g. Thus the whole length of the closely-massed core is keyed upon the shaft, whereby all parts of the core receive motion directly from the shaft,and the difficulty above described is obviated.

In order to insulate the core from the shaft, whereby the heating which would otherwise occur at points of contact of the core and shaft, due to local currents in the core, is done away with, I wrap or surround the shaft and the continuous key with mica, t'.

I have shown the mica, i, as not extending IOO key, a number of thin iron plates slotted to jt under the thick end and middle disks, since this is not usually necessary. It may, however, be extended to these parts, if desired. I prefer to use mica as the insulating material; but other suitable material may be employed.

In the construction shown in Fig. 3 the shaft A has screwthreadsk k at each end of the core B, and the key gextends continuously between these screw-threads. The thick end plates, b, preferably, are beveled on their outer sides. All the core-plates are provided with slots fitting the key g, as before. A heavy nut, l, is placed on the shaft at each end of the core, and these nuts are screwed up tightly againstv the core, so as to bring all the plates into close mechanical contact, they being insulated from each other, as already described. The insulating-wrapping, i, surrounds the shaft and its key. In this easeIhaveshown it as placed beneath the thick core-plates as well as the main body of the core.

Itwill be seen that by the construction above described I provide a compact, strong, du rable, and well-insulated form of armature, free from the defects which I have mentioned.

Vhat I claim is* 1. An armature-'core having in combination a shaft provided with a continuous rib or the rib or key, insulating material between said plates extending throughout their opposing surfaces, and means clamping said thin iron' plates and intervening insulating material t0- gether into a solid body without air-spaces between the plates, substantially as set forth.

' 2. An armaturecore having in combination a shaft provided with acontinuous rib or key, a numberof thin iron plates slotted to fit the rib or key, insulating material between said plates extenc'ling throughout their opposing surfaces,and bolts extendinglongitudinally l through the armature and clamping said thin iron plates andintervening insulating material together into a solid body without ai r-spaces between the plates, substantially as set forth.

3. The combination of a shaft having a con tinuous rib or key, a covering of insulating material upon the shaft and key, and an armature-core consisting of a number of thin iron plates insulated from each other and massed closely together upon the shaft, and all of said plates heilig provided with slots fitting said key, substantially as set forth.

4. The combination o't'a shaft having a continuous rib or key, a wrapping of mica around the shaft and key, and au armature-core consisting of a number of thin iron plates insulated from eac-h other and massed closely together upon the shaft, and all of said plates being provided with slots fitting said key, substantially as set forth.

This specification signed and witnessed this 19th day of February, 1887.

CHARLES B TCH ELOR.

Vt nesscs:

WM. PnLznR, E. C. RowLAND. 

